Heat-exchange apparatus



H. NIELSEN AND F. D. MARSHALL. HEAT EXCHANGE APPARATUS. mucmou FILED sgrr. 1 1. 1920. 1,378,71 5 Patented May 17,1921.

I I l I I Nl l -I I I I INNN I l l li Ill lllilillllilll I u. l -1\ UNITED STATES PATENT OFFICE.

HARALD NIELSEN, or mrnnnnsnx, AND rnnnnnrcx BEACON MARSHALL, or wnskr- MINSTER, LoNnoN, ENGLAND.

HEAT-EXCHANGE APPARATUS.

7 Specification of Letters Patent. f'atgnted lu y 17 1921 Application filedSeptember 11, 1920. Serial No. 409,663.

To all whom it may concern:

Be it known that we, HARALD NIELSEN, a subject of the King of Denmark, and F RED- nnrox DEAGON MAnsHALL, subject of the King of Great Britaimresiding at, respectively, l8 Firs avenue, Muswell Hill, Mid dlesex, England, and 19 'Queen Annes Chambers, Westminster, London, England, have invented new and useful Improvements in Heat-Exchange Apparatus, of which the following isa specification.

Our invention relates to heat exchange apparatus or superheaters for use in connection with producer-gas plant, or plant for the reheating of coke oven gas.

For the purpose of our invention we employ an apparatus for effecting an exchange of heat which comprises a closed casing or container within which is arranged a series of flat, oblong closed boxes connectedtogether by short pipes so as to provide a continuous passage for the gas, such as a mixture of steam and air, to be heated, the boxes or heating units being furnished with in ternal bailie plates to increase the path through which the said gas or mixture is made to travel, and also so disposed relatively to one another as to provide a Zigzag passage. The space between the said boxes or heating units and the inner surface of the casing through which the heating gas or mixture of gases flows is made of such dimensions that the velocity of flow ofthe latter is relatively slow, thereby facilitating the deposit of dust by gravity upon the upper surfaces of the boxes, the under or more efficient heating surface of the said boxes being left clean for the trans mission of heat to. the gas passing through said boxes in the most eiiicient manner.

In connection with an apparatus of the above construction we provide the casing or container with cleaning doors and scrapers, the latter of whichmay be operated either by handor mechanically so as to enable the removal of the accumulated dust to be effected during the actual working of the apparatus, without interfering with the continuous operation of the apparatus. It will also be understood that it is possi- .ble to provide a large heating surface in a relatively small container or, in other words, to reduce the loss by radiation, to the outside atmosphere to a minimum owing to the restricted surface air.

The container is extended downward so presented to the outside as to form a receiver or hopper for the dust collected, which can then be removed con-' tinuously or intermittently by any well known contrivance. Furthermore, a portion of this'collector can be provided with an inlet openingfor the heating gas from the producer or other source and be arranged with internal division plates and the lower portion of the. casing filled with water so as to form a water seal, to enable the part of the receptacle containing the heating boxes or units to be cut off from the said producer or other source if desired.

The troublesome expansion due to the high temperature is effectually compensated for by the arrangement of the heating boxes in the manner described above without the employment of special expansion pieces such as are found necessary with heat inter changers of the tubular type.

The heating boxes are preferably of the same width asthecasing, but have their ends spaced a distance from the front and rear walls of the casing, and adjacent to each of said boxes a damper is arranged, which dampers are located adjacent to opposite ends of alternate boxes so that when these dampers are closed, a tortuous or zig zag passage is provided around all of the boxes. By opening any one of these dampers, a short cut is provided pastthe adjacent box, thus eliminating its heating agency when desired.

In heat interchange apparatus as now generally constructed the gases leaving the apparatus still containing a large amount of sensible heat are conducted away to scrubbing apparatus by means of an uninsu lated pipe, or, if a number of interchangers are employed, by means of a common main, the object of which is to cool the gases. By adopting this method a certain amount of heat is lost. Furthermore, the pipe or main conducting the'steam and air or other blast to the heat-interchanger or interchangers is generally heavily insulated in order to prevent cooling and consequent condensation of the steam in the mixture. Now, according to our invention we place the steam and air or other blast pipes or which two results are obtained, namely, the hot gas is further cooled and the steam and air or other blast is pre-heated to any desirable extent within the limits of the heat available and the condensation of the steam is far more efiiciently prevented than by simply lagging or insulating the blast-pipe or main, the hot gases surroundlng the steam and air or other blast acting as a most effective insulator.

To enable the invention to be fully understood we will describe it by reference to the accompanying drawing in which Figure l is a sectional elevation of a heatexchange apparatus or super'heater for producer-gas orcoke oven-gas constructed'according to the invention, and

Fig. 2 is a sectional plan view thereof.

(4 indicates the closed casing or container, 7) the series of fiat closed boxes,which are here shown of an oblong or rectangular shape, 0 the short pipes which connect the said closed boxes together so as to form a continuous zig-zag passage for the gas or mixture to be heated, and (Z the internal bafiie plates provided in the closed boxes or heating unitsb to cause the said gas or mixture to follow a tortuous path through each box. a is the inlet pipe by which the gas to be heated enters the topmost box or unit b and j is the outlet pipe by which the said gas leaves the apparatus after having passed through the extended tortuous and zig-zag path indicated by the arrows. 9 indicates the inlet to the casing a for the heating gas or mixture and h the outlet therefrom, the said gas or mixture flowing through the easing in a direction opposite to that of the gas to be heated, as shown by the arrows, and in the zig-zag space or path provided between the ends of the units 6 and the inside of the casing. The cross sectional area of this space is much greater than that of the inlet pipe so that the gas entering the casing will expand and flow more slowly through the casing than through the pipe 9 and thus afford time to transmit its heat to the gas within the boxes Z). As shown in Fig. 2, the boxes 7) are of substantially the same width laterally as the casing, butare spaced from the front and rear walls of the casing, and dampers i are located in these spaces at opposite ends of alternate boxes as shown in Fig. 1. hen these dampers are closed, as therein shown, the heating gas will be forced to take a zigzag path around all of the boxes 6. The opening of any one of these dampers will provide a short cut for the heating gas past the adjacent box and prevent its receiving as much heat from the heating gases as it would receive were the damper to remain in closed position. These dampers may therefore be used to regulate the temperature of the gas to be heated.

j shows the scrapers which are provided in connection with the units Z) for the purpose of clearing deposited dust from the upper surfaces of the said units. These scrapers, in the arrangements illustrated, are designed to be operated by the handles in) which extend through doors Z provided in the casing.

The lower end of the closed casing a is extended downward to constitute the hopper or collector m into which the deposited dust gravitates and from which' it can be removed in any convenient way. The inlet g for the heating gas opens into this hopper and adjacent thereto there is provided the internal divisional plate or deflector n and the lower portion of the casing may be filled with water, as indicated by the dotted line 7* up to a point above the lower end of the deflector a to form a water seal, so that the casing may be cut off from the producer or other source of heating gas, if desired, with out permitting the escape or back flow of gas to the pipe 9.

The hot gases leaving the casing by the pipe h enter the main 0 and through this main there extends the main 7) through which flows the gas to be heated before pass ing by the pipe 6 to the exchange apparatus. By this means, as above described, the said gas is pre-heated and condensation is effectively prevented. I

Claims.

1. In a heat exchange apparatus, a closed casing having inlet and outlet openings for one of the heat exchanging mediums, a series of closed boxes located within the casing and connected together to form a continuous zigzag passage, inlet and outlet pipes for the other heat exchanging medium connected with said boxes, said boxes being of substantially the same width as the casing, and providing 1 spaces between their opposite ends and the adjacent wall of the casing, and dampers located in said spaces adjacent to opposite ends of alternate boxes.

2. In a heat exchange apparatus, a closed casing having. inlet and outlet openings for one of the heat exchanging mediums, a series of closed boxes located within the casing and connected together to form a continuous zigzag passage, inlet and outlet pipes for the other heat exchanging medium connected with said boxes, said boxes being of substantially the same width as the casing, and providing spaces between their opposite ends and the adjacent wall of the casing, and dampers located in said spaces adjacent toopposite ends of alternate boxes, theinlet pipe for the first mentioned medium being located adjacent to the lower end of the cas ing, and a downwardly extending deflector within the casing adapted to extend below the surface of a body of water in the lower end of the casing to form a water seal.

3. In a heat exchange apparatus, a'closed casing having inlet and outlet openings for casing, and dampers located in said spaces one of the heat exchanging mediums, a seadjacent to opposite ends of alternate boxes, ries of closed boxes locatedvwithin the casa supply pipe communicating with the inlet ing and connected together to form a conto said boxes, and a delivery pipe connected 5 tinuous zigzag passage, inlet and outlet to the outlet of the casing and having a porl5 pipes for the other heat exchanging medium tion surrounding a portion of said supply connected with said boxes, said boxes being pipe.

of substantially the same Width as the casing, and providing spaces between their op- HARM-D NIELSEN- 10 posite ends and the adjacent Wall of the FREDERICK BEACON MARSHALL- 

